Typewriting machine



1,630,384 May 31, 1927. w F. HELMOND TYPEWRiTING maximum Filed March 20, 1924 waumz y I Av /Z27 Patented May 31, 1 927.

*ni'rs STATES f 1,630,384? PATENT- oFF c WILL AM'F. HELMOND, 0F 'HAR'IFORID, connnorrour, assrenon To unnnnwoon TYPEWRITER COMPANY, on NEW YORK, N. Y., A CORPORATION or DELAWARE.

' TYPEWRITIN MACI-HNE,

. Application filed March 20,1924 Serial No. 700,4 0.

The invention is in the nature of an improvement on Patent No. 1,414,? 38, granted to me May 2, 1922, in which a lightspring tends constantlyv to'thr ow a back-spacing dog into mesh with the carriage-rack. Said meshing spring must be overcome by the tension of a second spring, the latter serving to restore the back-spacing devices to normal positions when the key is released; it being part of the duty of said returning spring to disconnect said back-spacer dog from the carriage-rack in opposition to the tension of the first-mentioned spring.

It is found in practice that considerable close fitting and adjustment isrequired in order to insure correct action of the back spacing mechanism, since the tension of the meshing spring must be suflicient for positlvely interengagmg the pawl with the carriage-rack at the start of the depression of the back-spacing key, whereas said meshing spring mustbe weakerthan said returning 1 spring, so that the latter may promptly disconnect the pawl from the carriage-rack.

Moreover, there is liability of the mechanism being put out of orderby attemptsof untrained workersfto adjust the relative tension of said springs. V

An object ofthe invention therefore is to avoid the necessity of opposing one spring by'another in the manner stated, to simplify the mechanism, to reduce the difii culty and expense of'assembling the parts,

and to overcome liability of trouble arising from. bungling attempts to readjust the tension. p A o One of the features vof the improvement consists in causing a; singlespring to'take the place of two opposing springs; and to,

this end anew spring is provided, which has a variety of actions and functions. The

new spring'is anchored upon an extended portion of the connecting link forming part ofthe back-spacing, mechanism, so thatsaid spring is capable of exerting upward pressure. The new spring co-operatesWith the back-spacing key to pull forward the backspacerpawl into preliminary mesh or engagement with the carriage-rack. I 7

Other. features and advantages willheref- .thelever 39, which is provided with a stop 41 thereon .tolimit the'swinging of thepawl 37 to the left in iFigure 2.; The pawl 37 v ina fter appean;

, p In the accompanying drawings,

ly in section, illustrating myinvention'as '25' and arm '27.

showing the back-spacing pawl in its normal position.

Figure 3 is a plan, partly in section,of'

the lower end of the connecting rod or pit man, showing parts connected thereto. 3 11 designates the platen of the' machine,

which is movably supported by a carriage 12, which slides on rails 13 and '14, and has connected to the under side'thereof a back-j spacing rack 15 by means of arms 16.

-Key-levers 17 are shown as 'pivotally. connected to a bridge l8v at the rear ofthe machine by means of a, rod 19, and are supported in their normalcposition bycompres- "sion-springs 20. A second bridge 21,'sit'u-' 7 atcd forwardly of said bridge 18, has

bell-cranks 22 ,pivotally connected thereto by means of arod 23. V

A back-spacing key 24; is mounted at the front end of a back-spacing key-lever 25f which is secured toa rook-shaft 26 at the left 'end thereof Said rockeshaft 26 has secured thereto, attl e right end thereof, an

arm 27,]which ispivotally connectedgto a short extension 28'at the lower-"end or ;a

connecting rod or] pitman 29,, forwardly.

thereof, by means of a -pin 30. r j

. The lower end of the pitman 29 has thereon also a spur 31, rearwardlyofsaid exten l, V

sion 28, which; terminates ina bend 33 at 1 right angles thereto, which bend is shown as having anchored thereto the lower end of'aflrestoring spring 32, the upper end'of which is shown as connected to a bracket 3% at the vfrontof said bridge 18; The spring 32 is preferably substantially 'verticalyand man .29 is pivotally" connectecl at 3 5,to a subcarrier39, which is pivotally connected at AOJto a stationary part ofthe machine, to

parallel to the key-lever swing in a plane initially strained. The upper end of the pit'-- i 7 ion - The pawl 37 is situated in a substantially 7 vertical plane-transversely to the plane of alsohas at thelowerend thereof; a spur 42 l the right side of the lever- 39 to limit the of the pawl 37 out ofmesh withtheraek 1'5,

' by the upward pressure of the pitman 29 produced by the, tensile'icourse' of the spring 32 exerted on the lower end of said pitman,

which accordingly tends'to drive the lever 39'to. the right, or at. least to -restrain it fromturning to the left. At Figure 1 the 'pitman- 29 and lever 39 form a nearly closed toggle. The upper end of the lever 39 101-- inally leans against-the neck of a stud 44;, which is secured to a stationary part of the machine, front'of theupper end of said lever the rear of theirack 15.

39 and.

l Vhen the key-lever is being depressedr -the arm 27 pulls downwardlyon theextension 28 of the pitman 29 by means of the pin 30. The spring 32, which is under tension, at suc'h downward pullhelps to turn the 'pitman 29- forwardly about pivot 30,

thereby swinging the lever 39 with the pawl 37 thereon forwardly thus opening the I I I n l f swlngs pitman 29forwardly, thus vlbrating nearly closed toggle until the upper end o lever 39 forwardly.

V the rear of the rack 15, or by the inn erj side of a hooked projection 45 at the rear of said lever 39 the'lever 39"is stopped by against the rear of. said stud 4:4. 7 This swinging of the lever 39 forwardly 1 brings the 'witl1 its tooth'43 into. mesh with the teeth on the under side of the rack b'efore'the pawl-37 isturned in its own plane by the continued action of the continued 'pitman"29*thereon, as hereinafter described; .40

When the above-described turning of the pitma ping of the swingingofthe lever 39,the

downward pull of thexarm 27 on the lower end of the pitman 29 stretchesthe saidjpitman' 29 downspring 32 and moves var'dl y. "The upper end .ofthe pitman then acts on the substantially horizontal arm 36 "of the pawl 37 ,andturns thelatterina clockwise direction in Figure 2, thereby mov 1 ing the rack to the right until the pawl 37 is stopped-when the spur'42 thereof i's encountered by the right side of the lever ing.

" 32'lifts. the pitman 29, which is then f thereby completing: one stroke of back-space {Vhen the key-lever is'released,"the

prevented by the pawl-and-ratchet' mecha- (shown in Figure2) fromyturningthe pawl 37 in a counterclockwise direction, while its tooth43 is in mesh with the ji'aelr' 15. The upward pressure of the pitjman'29, therefore, swings; the lever 39 with the pawl'ifi thereon backwardly to the origi nal toggle-closing position of said lever 39, thereby bringing the tooth 43 of said pawl leaving a small space, between the,

n 29 isjdiscontinued, throughthe stop v I p "substantially 'aidedby'the, spring 32. Said 'spr1ng'32, regarded in one .way, is in" the .37 out of mesh with the rack 15; whereupon the continued upward pressure'of the spring and .pitinan 29 turns the pawl 37 on its pivot inja ;counterclockwisedirection Figure 2,

u i i t wepted byxth St@P -el1 h lever 39, thereby bringing the pawl. 37 to itsorigina'l position, when the back-spaoing 'thepin '30 at thelower end of the pitman '29 situated at a distance '29 from its con- -1]6Ct1()1'lWltl1 thelower end of the spring 32, forwardly thereof, and by having said spring initially strained,the initial depressilon of pivot permits the tensioned spring j 32 to open the toggle, i."e., thepitmandis causedto swing'the lever 39 witlithepawl thereon ;forwar 'dly,'- thereby bringing the teeth 43 of the pawl 37-into mesh with the rack l5 be'fore said pawl ist urned inyits planeforbac'lpspacing by thecontinuedad tion of the pitinan thereon. -So {long as pivot 30 is-held up by 'thespr-ing the latter cannot open the toggle, but when said pivot 30 is initially depressed by'the-key. '24, said,

spring instantly opens: the toggle 1. .e.,

fore, eliminated, together with the labor of V kfittlng it into position in the machine. 1

Itwill be understoodthat'at the "clown ;ward start of. the key-lever 25, the pivot 30 descends, thereby tending @to operate through link 29 to pull the unit "(comprising 39 and V "37) forwardly around-pivoted "This ten dency 7 of said unit to swing around is nature ofalfulcrumforanelbow-leverfcomprising the long arm 29 and the shortrarm 29, so that the downward movementof 'the swing forwardly the upper end of long arm 29. During th s forward-swing of said unit 39, *37, and the consequent engagementof the tooth or: dog -453lwith the carriage-rack there is no slgnificant downward 'move-. 'ment at 31 or 33, on account of the resistance o'fl'ered by tlie spring 32. 'It is alsonoted the unit compris ng 39, 37 to swingwfor wardly about the pivot--40 ('thus'engaging "the. dog with the 'ra'ek) .than itisfor the 'li-nk29" toadescend in opposition to the re sistance offered by the'spring 32, *He'nce'fat "free forward end of the short arm te'n dsto I the start of a key the dog 43 swings -for- I wardlyaround pivot into mesh with the rack, and, on further descent of the key, the

dog' 43 is forced to-swingaround pivot 38, thereby back-spacingthe carriage. Upon relief of the key from pressure, the spring 32'has the effect of thrustingup the link or pitman 29 and causing it to swing the unit 39, 37 backwardly about -the pivot 40, 107

until the dog 43 escapes from the rack, in-.

asmuch as it is easier for the dog to move in this directionthan it would be to force its way in a dlreotion endwise of the rack.

lVhen thedog has escaped from the rack, thespr1ng 32 through link 29 swings the dog about pivot 38 and completes the return ofall'the other parts to normal positions.

The connecting link 29 is under constant tension to turn around pivot 30 in forward direction, by reason of spring '32, but, on

' account of greater pressure upward exerted by spring 32 said link 29 tends to turn39 cannot move in two divergent arcs, one

to the right, and'thereby' the link is restrained from turning to'the left or for wardly, and hence the forward action of the link does not take place until the back-spacer key-lever is depressed.

'- The forward action of the back-spacer pawl 37 and carrier 39 around pivot 40 is principally due to the fact that when depressing the back-spacer key-lever 25, the upward pressure of the spring 32 is counteracted and the pivot 30 is'depressed,'- so that the forward pressure of the spring on the link is permitted to swing the lever 39 and" upwardly as well as forwardly around pivot I 30, whereas the pivot 35 (where 29 is atv tached at its upper end) wouldhave to swing downwardly as well as forwardly about .pivot 40. The tendency to upward movement of link 29 around pivot 30 would be resisted by the tendency to downward movement of 39 around pivot 40. The point 38 about pivot 30 and theother about pivot 40. Pivot 30 must move down in order to enable pivot 35 to swing forward and down. Spring 32 prevents 30 from moving down,

until the spring is overcome by pressure on the key 24. v r

Variations may be. resorted to within the I, scope of the invention, and portions of the improvements may be used without others. Having thus descrlbed my invention, I claim:

1. In a typewriting machine, the combina to turn said pawl in its plane, thereby movtion of a platenya carriage forniovably' supporting the same, and means for backsoacin said carria e I said means com ris- 2: c a

ing'a rack connected to said carriage, a

back-spacing lever -pivotally Qmounted to swing in a vertical planetran'sversely to the rack, means for stopping the forward 'swingingjof the lever, 'a pawl pivotally connected to'said lever and carriage thereby, to swing in a substantially vertical plane-transversely to the plane of-said lever, a tooth on said pawl to engage said rack, said le'vernormally keeping said pawl'out of mesh with said rack, a pitman pivotally connected at the upper end thereof to said pawl and, through said pawl, to said lever, and a spring supported at one end-thereof and connected at the other end thereofqto the pitman, combined with means to be applied for drawing said pitman, substantially downwardly, the point of application of said drawing meansgbeing situated for- 1 wardly ofthe connection of saidspring to said pitman,-with"a space therebetween, the, 1

forces 0f said spring'at said pitmanand of said drawing means with said space therebetween therebyforining a couple to '.'turn said pitman in a plane parallel to said'lever, swlngmgsaid lever-forwardly, and bringing said pawl into nieshwith'saidrack until sald lever is intercepted by said stopping means, and the continued application offsa-id drawing means to said pitman thereupon ing the rack for back-spacing the carriage 2. In a typewriting machine having a carj riage and a rack, a back-spacing mechanlsm for the carriage comprising a key-operated lever, a link extending therefrom, a backspacing dog movable by said link first laterally into mesh withsaid rack and then ina direction longitudinal ofthe rack to back-space the carriage, anda single spring connected to said link-to tend to co-operate with the key to shift the dog into meshwith the rack at the start of the depression of the back-spacer key, and to return all the parts to normalpositions at the relief-of i the key-. from pressure, saidlink being in the ,form of an elbow-lever, one 'arm of the elbow-lever being connected, to the keylever and the. other arm being'connected to a said lever-to cooperate therewith in shift the back spacing dog to shift itv into mesh with the rack, and said spring connected to the elbow to serve asa yielding fulcrum for ing the dog at the beginning of the keystroke.

I In i t-t' achine having carriage and a rack, a back-spacing mecha-i nism for the carriage comprising a keyoperated lever, a link extending, therefrom, 2'

a backspacing dog movable" by said -link first laterally. into mesh with said rack and then in a direction longitudinal of the rack Tao to backspace thecarriageyand 2a single ,spring connected to said link to tend to cooperate Withthe key to shift the dog into such movement of the rocker, said spring also effective to turn-the dog upon its own pivot; said spring being also effective upon relief-of the key'i'rom pressure first to swing the :dog and rocker to unmesh the dog from the rack, and then to sWingt-he dog-upon itsgown pivot to normal position.

4. In a :typewriting machine having a letter feeding carriage provided with a rack Y and a back-check device therefor, .thecombh nation of a back-spac ng keyand ajt'ourmotion back-spacingmechanism. controlled by said key and inclndin'g a ,pivoted backdpawlnormally out of engagement with .sai rack, a lever Whereon saidpawl is mounted, said lever pivoted to vibrate in a plane at right angles-to said rack, and said pawl mountedto vibrate in a plane parallel With said rack, a tourJnotion link pivoted at one end to said. pawl and capable of swinging-the lever to carry the pawl bodily'into and out ofmesh iththe rack, and also oaable of vibrating the pawl independently of said lever to back-spacetl e rack, and of mamas 1 restoring the pawl ,vvhenifree from the rack,

a-lever armoperable by said keyland pivoted to the other end of said link, and a single spring connected to said link to swing the link about its pivotalconnectionto said lever arm, and maintaining the lever arnnlink, pawl and pawl-lever in normal positions.

- 5. In. a typewriting maehine having aletter-teeding carriage provided with a raok and a back-check device therefor, vthe combination'of a back-spacing key 'and' a four-i motion backspacing mechanism .controll edi by said key and including a,pivoted backspacing pawl normally out otengagement u'ithsaid rack, a leverwheroon .saidpawl is mounted, said lever pivoted to vibrategin a plane at right angles ,to said rack, and said pawl mounted to'-v1b1'ate, n qa plane parallel V a four-mot on l nk pivoted with said rack, at one end tosaidpawland capableiof swing ing the lever to carry the pawl ,bodily into and out of mesh with the rack, and also @cap able of vibrating the p awl independently of said lever ;to back spacetherack, Qandof I rest oring the pawl when .free' from the rack,

a lere'rarm.operable by said keyv and pivoted j to the other end of said link, and a spring connected to said link andvm'aint aining the lever arm,'l1n k, pawl and pawl-lever in .nor-

mal positions said link having a crossearm engaged by said spring between the pivot of the lever arm and the point ofpivotalcon nection of the link to the lever arm.

WILLIAM HELMOND; 

